Formula: Cu5FeS4 Orthorhombic Description: Bornite forms as a primary hydrothermal precipitate or a later supergene replacement mineral. It occurs with other copper minerals such as covellite, malachite and azurite. It is marked by its intense purple to …
Taylor County
Calaverite
Formula: AuTe2 Monoclinic Description: Calaverite with pen for scale. From the mineral collection of Brigham Young University Department of Geology, Provo, Utah, Mineral Specimens 185. Courtesy of the U.S. Geological Survey Denver Library Photographic Collection. (Photo by Andrew …
Chalcopyrite
Formula: CuFeS2 Tetragonal Description: Chalcopyrite is an important ore of copper found in a wide range of hydrothermal environments. It is often associated with sphalerite and galena. It oxidizes to form copper minerals such as malachite, azurite, …
Gold
Formula: Au Isometric Description:Gold is usually found in hydrothermal deposits where it forms at a wide range of temperatures and geological settings. Gold may form in exhalative deposits formed on the sea floor associated with Archean …
Krennerite
Formula: (Au,Ag)Te2 Orthorhombic Description: Krennerite is a rare mineral found in hydrothermal deposits. TAYLOR COUNTY: Krennerite is found as small grains intergrown with pyrite, chalcopyrite calaverite, petzite and other minerals in the hypogene ore at the Bend Deposit, …
Petzite
Formula: Ag3AuTe2 Isometric Description: Petzite is a steel-gray granular mineral found in hydrothermal deposits associated with other rare tellurium, gold and silver minerals. RUSK COUNTY: Petzite is reported as a component of the ore at the Flambeau Mine, …
Pyrite
Pyrite is the most common sulfide found in many environments. It is a common accessory mineral in igneous, sedimentary and metamorphic rocks. It also is abundant in most hydrothermal deposits. Only the most significant occurrences …
Tetrahedrite-tennantite
Formula: (Cu,Fe,Ag,Zn)12(Sb,As)4S13 Isometric Description:Tetrahedrite forms a solid solution series with tennantite and freibergite in moderate to low temperature hydrothermal deposits.DOUGLAS COUNTY: Irving (1882) reports finding tetrahedrite in “small quantities in traverse veins in copper-bearing rocks”. This occurrence has …